This invention relates to the field of apparatuses for processing radionuclides.
Positron Emission Tomography (PET) is a powerful tool for diagnosing and treatment planning of many diseases wherein radiopharmaceuticals or radionuclides are injected into a patient to diagnose and assess the disease. Accelerators are used to produce the radioisotopes used in PET. Generally, an accelerator produces radioisotopes by accelerating a particle beam and bombarding a target material, housed in a target system, with the particle beam.
In certain cases, the product of bombardment needs to be further processed to produce a substance suitable for injection into the human body. For example, [18F]fluoride ions are commonly produced with an accelerator and appropriate target. These ions must be farther processed to produce [18F]FDG (x2-deoxy-2-fluoro-D-glucose), this process is typically referred to as radiosynthesis. Because of the radioactivity of [18F], it is desirable to automate as much of the processing as possible to avoid human exposure to radiation.
One apparatus which is currently employed includes a glassy carbon reaction vessel in a heating block fabricated from aluminum. The reaction vessel is in direct contact with the heating block to heat and cool the vessel. This system, as well as many other aspects of automated synthesis, is discussed in a paper entitled xe2x80x9cIntroduction: State of Art in Automated Syntheses of Short-Lived Radiopharmaceuticalsxe2x80x9d by Jeanne M. Link, John C. Clark and Thomas J. Ruth, Targetry ""91. pp 174-185. More specifically, at page 180, Nebeling discusses this system indicating a heating/cooling range of xe2x88x92200xc2x0 C. to +200xc2x0 C. and a time span of approximately 1xc2xd minutes to change the temperature. Further, at page 183, Nebeling refers to an automated FDG system which is self cleaning. He specifically indicated that the key to success was the use of the glassy carbon reaction vessel.
Although the prior art system has proven somewhat successful for the production of FDG, the design of this system does not allow for rapid temperature changes or control of temperature gradients. Further, thermocouples do not directly measure the temperature of the solution, rather they measure the temperature of the heater block. Moreover, the glassy carbon reaction vessel is custom machined and expensive.
German Patent DE 195 15 212 A1 discloses a method for processing [18F] fluoride ions to produce [18F]FDG, which can be employed with an automated synthesis device.
Therefore, it is an object of the present invention to provide an apparatus for processing radionuclides which provides the capability of rapid temperature change.
Further, it is an object of the present invention to provide an apparatus for processing radionuclides which provides the capability to heat and/or cool two different regions of the reaction vessel.
It is another object of the present invention to provide an apparatus for processing radionuclides which utilizes infrared temperature sensing.
It is yet another object of the present invention to provide an apparatus for processing radionuclides wherein the reaction vessel is closed.
Moreover, it is an object of the present invention to provide an apparatus for processing radionuclides wherein the reaction vessel is disposable.
Other objects and advantages will be accomplished by the present invention which serves to process radionuclides in an apparatus which utilizes a reaction vessel for processing the radionuclides therein. The apparatus for processing radionuclides is generally comprised of a block which defines a vessel receptacle, an upper temperature changing means and a lower temperature changing means. The vessel receptacle defines an upper zone and a lower zone and is configured to receive the reaction vessel therein in a manner such that an upper zone space is defined between an exterior of the reaction vessel and an inner wall of the vessel receptacle in the upper zone. Likewise, a lower zone space is defined between an exterior of the reaction vessel and inner wall of the vessel receptacle in the lower zone. The upper temperature changing means serves to alter the temperature of gas in the upper zone space and the lower temperature changing means serve to alter the temperature of gas in said lower zone space. The temperature in the upper and lower zone are independently controllable.